The present invention departs from the tubular moisture-absorbing apparatus disclosed in U.S. Pat. No. 5,676,739 (Gustafsson) designed for vertical disposition in, for instance, a closed steel container for transport of humidity-sensitive goods. The apparatus is made of a polymer coated board which provides required stiffness. Starting from its upper end, it comprises, in a longitudinal direction, a chamber with a moisture-absorbing material, such as calcium chloride, which forms an aqueous solution on contact with humid air. The salt solution is continuously drained into a lower liquid collection chamber in form of a plastic container with which the upper chamber is in communication. The particulate desiccant material is retained in the upper chamber by sieve means comprising a non-return valve means. Contact of the desiccant with ambient air is ensured by a netting element located in front of an opening in the wall of the upper chamber. The netting element is designed to prevent the aqueous solution from leaving the upper chamber through it rather than through the sieve means. Prior to use the netting element and thus the opening in the wall of the upper chamber is closed by a removable plastic foil.
While the moisture-absorbing apparatus of Gustafsson has been shown to function well in industrial practice, there is room for improvement. In particular, the known apparatus is bulky. This is a disadvantage in transport and storage prior to use.